Circuit controller



July 10, 1934- R, c. DA COSTA CIRCUIT coNTRoLLE Filed May lO, 19322 I NV EN TOAR. 5055/? /is/Z A TTORNE Y.

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Patented July 10, 1934 UNITED STATES PATENT OFFICE CIRCUIT CONTROLLERApplication May 10, 1932, Serial No. 610,392

8 Claims.

This invention relates to circuit controllers, and particularly tooscillating snap switches.

It is among the objects of the invention; to provide a snap switch ofcheapness and simplicity of construction while maintaining a higheciency and'long life; to reduce the number of parts formerly necessaryin constructing snap switches; to provide a snap switch with contactswhich engage with certain areas in physical contact to close a circuit,and which disengage with different areas in disrupted physical contactto open a circuit to minimize wear on the contacting areas; to provide asnap switch having means for securing resilient guided oscillation of asnap element, with means for positively moving the snap element for aportion of its oscillation; to provide a snap switch which automaticallycleans its own contacts; to provide an improved bearing for oscillatingshafts; to provide a snap switch of low series resistance; to provide asnap switch with an improved motion limiting device; to provide a simpleand compact snap switch of improved character; to improve the snapmechanism in switches; and many other objects and advantages as willbecome more apparent as the description proceeds.

In the accompanying drawing:

Fig. 1 represents a transverse horizontal section with the parts insubstantially mid position,

Fig. 2 represents a transverse vertical section partially in full lines,with the parts in one extreme position,

Figs. 3 and 4 represent fragmentary details.

The invention is illustratively disclosed as embodied in a small compactunit suitable for use in radio sets and the like, although obviouslyapplicable to general circuit controlling purposes. In its preferredembodiment, at least one pair of contacts are provided in fixedrelation, and the circuit is controlled by a bridge piece movable with asnap action relative to the fixed contacts.

A shell is provided comprising a bent piece of sheet metal forming anend wall 10, having a central recess or depression l1, a side Wall 12having a bearing opening 26, and an end wall 13, which all may be formedby a stamping. The free ends of the end walls and 13 are secured inanchoring wall 14 which may carry integral tabs or anchoring ends 15 bywhich the unit may be secured in a desired location. Anchoring Wall 14has a semi-cylindrical opening 16, opposite to and in registration withthe bearing opening 26 in the opposite side wall l2. The' respectiveopenings are relatively close to end Wall 13. Partially cylindricalopening 16 contains a V-shape tongue (Cl. 20D-68) 17 formed, preferably,integrally with the anchor wall 14. 'In the form disclosed the V orwedge shaped tongue is substantially a sector of the opening 16, and hasa terminal tip 18 substantially at the axis of the opening. The sectortongue 17 is illustrated as forming a little less than 90 of the opening16, although as will be pointed out the arcuate extent of the tongue maybe varied in accordance with the limitations desired upon theoscillations of the associated shank to be described. It will be notedthat the respective edge faces 7 and 8 of the tongue 17 form stops forthe associated shank.

A sheet of insulating material 20, may be provided as a lining of theshell. The open sides of the shell are closed byrigid insulating sheetsor plates 21 and 22, suitably anchored to the edges of the respectivewalls. The plate 22 carries a pair of fixed but slightly resilientcontacts 36 and 37. These contact elements may also be duplicated onplate 21 if it is desired to provide a controller for two separatecircuits instead of for one circuit as illustrated.

A control piece comprised of an oscillating shank or rock-shaft 23 isprovided, which may be described as partially cylindrical in that it hascylindrical surface 24 of substantially the same curvature as theopening 16, and' has a fiat side 25 extending longitudinally of theshank. The flat side 25 may be described as having two surfaces 5 and 6merging or meeting substantially on the median line of the face 25 whichas illustrated is coincident with the axis of the shank. The respectivesurfaces 5 and 6 are arranged for engagement with the respective lstopsurfaces 7 and 8 of the stop tongue 17. It will be clear that thesurfaces 5 and 6 may have angular relation to each other diiferent fromthe 180 relation disclosed. 'I'he variation in angular surface relationand a variation in the angular relation of the stopv faces 7 and 8 oftongue 17 may be utilized to vary the degrees of oscillation permittedto the shank or shaft 23, it being understood that the shank 23 isoscillatably received in bearing opening 16. The shank extends throughopening 16, and the arcuate surface 24 slidably engages the annularsurface of the opening 16. The tip 18 of tongue 17 extends close to andalmost touches the face 25 of the shank. A slight tolerance is advisableto permit free oscillation depending upon the accuracy of the machining.The end of shank 23 is journalled and anchored in bearing opening 26 inwall 12. Any desired operating mechanism may be mounted on theouter'qfree spring,

end of shank 23, to permit manual or other oscillation of the shank.

A guiding plate 27, having a guide groove 28, is rigidly mounted uponthe flat side or face 25 of the shank, with the groove extendingparallel to the face 25. The attachment may be by any desired means suchas by ears 30 upset in suitable transverse slots in the surface 24. Theplate has stops 31 extending outwardly in alignment with butsubstantially perpendicular to the groove 28.

The movable contact element or bridge comprises a substantiallycylindrical insulating element 32 having an internal axial bore 33having an internal shoulder 29, and having a tapering rounded end ornose 34 arranged for guided sliding engagement with the surface ofgroove 28 in plate 27. A metallic sleeve 35 is rigidly mounted on thecylindrical element 32, in position and of such diameter as tofrictionally engage the spaced contacts 36 and 37 upon suitable verticalpositioning of the element to an extreme position. A guide pin 38 havingflange 40 has one end seated in depression or recess 1l in end wall 10,and the other end slidably disposed in bore 33 of' the insulatingelement 32. A helical spring 4l surrounds the pin 38 and engages betweenthe flange 40 and shoulder 29 of the element and urges the elementtoward the groove in plate 27. The resilient spaced contacts 36 and 37have each an extension 43 and 44 including terminals for attachment ofsuitable connecters for the circuit to be controlled.

vIt will be understood that the nose 34 of insulated element 32 is heldagainst the guiding plate 27, in its groove 28, by pressure from helicalspring 41, and normally at an end of the plate in contact with one orthe other of stops 31. With the nose 34 in the end of the groove 28, it

will be observed that perpendicular stop 31 endsadjacent the roundednose well back from the tip thereof.

It will be appreciated that with the contactor or bridge in one extremeposition, oscillation of the shank causes pressure on the plate 27 toforce the contacter axially toward end wall 10, on'the guide pin 38,thus compressing spring 41. Through frictional engagement of the ends ofthe spring, its compression4 is accompanied by relative rotative motionof the end turns of the Which imparts a twisting motion to the contactduring its axial movement which effects a wiping or cleaning action uponthe stationary contacts 36 and 37. This may be enhanced by causing theguiding plate to be canted a trifle, so that the rounded nose has arotation imparted to it during its slide from one end of the plate tothe other during an oscillation of the shank 23.

It will be understood that the insulating bridge element 32, guide pin38, and coil spring 41 comprise a telescoping unit resiliently*urgecl toextended relation, and the arrangement of recess 11 relative to the axisof the shank cr rock shaft 23, lying in a plane transverse of the shellsubstantially medially thereof, enables the pivotal mounting of one endof the telescoping unit to swing on an axis lying substantially in saidplane while the free end of the telescoping unit, the nose 34 of theelement 32, is guidably disposed in the track or groove 28 of the guideplate 27. Actuation of the rock shaft imposes endwise pressure on thetelescoping unit from stop 31, sliding the cylindrical bridge sleeveaxially relative to the fixed contacts 36 and 37, thus wiping same, aspreviously noted. Owing to the change of angular position of the rockshaft and its rigid guide plate, the compressing action urging thetelescopic unit to retracted relation is accompanied by the impositionof lateral pressure on nose 34 back of its tip, from the end of adjacentperpendicular stop 31, which forces the nose 34 out of the end of thegroove 28 and starts or initiates its sliding movement toward the otherend of the groove. This initial impetus thus positively given the snapelement is accompanied by a further change of angular relation of theguide plate until the angle of the guide plate groove is such as toenable the outward urge of the spring 41 to cause the nose 34 to slidealong the inclined groove to contact with the opposite stop 31, and tosnap the unit on its axis in recess 11 past dead center to its oppositeadjusted disposition.

It will be understood that although the first part of the snap movementis a positive movement of the snap element, yet the final part of themovement is a true resilient snap action lodging nose 34 in the pocketformed by the end of groove 28 and stop 31. The reverse snap movement,incident to an opposite oscillation of rock shaft 23 will have the samecycle of movements, namely, an initial positive movement and a finalsnap action. This snap operation when taken in connection with thetelescopic expansible unit, provides an important advantage of thisinvention, in that the relation of the cylindrical bridge element 35 tothe contacts B6-and 37 differs as to whether contact is being made orbroken. Thus the sleeve 35 is moved axially rearwardly (toward pivot 11)relative to the iixed contacts, owing to the positive telescopingat thebeginning of the circuit breaking movement, so that the sleeve separatesfrom the contacts in a retracted position. On the reverse or circuitmaking movement, the retraction of the sleeve at the beginning of themovement incident to telescoping the unit is without effect relative tocontacts 36 and 37 (in the single circuit control shown) as the snap tobridging circuit closing is accompanied .by an expansion of the unit sothat the sleeve is advancing axially or forwardly at the instant ofengaging contacts 36 and 37. This contributes to the long life of theswitch.

The operation and obvious advantages of the invention are thought to beclear from the foregoing description.

I claim:

1. In circuit controllers, an oscillatable shank, a guide plate mountedon the shank and having a guiding groove, a pair of contact elementsdisposed in spaced parallel planes substantially parallel with thegroove, a cylindrical bridge element having an axis substantiallyparallel with the plane of the contact elements', means on the bridgeelement in sliding guiding engagement with the groove, means urging saidlast mentioned means into engagement with the groove, 'and means forlimiting the oscillations of the shank on each side of dead center ofthe bridge element, a metal sleeve disposed concentrically on saidelement in position to frictionally engage the contact elements.

2. In circuit controllers, a frame, including an element having adepression, a shank journalled on the frame with its axis substantiallyin alignment with the depression, a guide plate having a groove andmounted on said shank and extending perpendicularly beyond said axis, aninsulating element having a tapered nose, a guide pin slidablyassociated with the element and engaging the depression, a springoperably associated with the element to urge it against the plate,contact means operably positioned, and a cylindrical contact elementcarried by the insulating element in position to bridge the contactmeans.

3. In snap switches, a shank, a frame, the frame having an annularopening, a segmental tongue extending into the opening, the shank havinga partially annular portion disposed in the opening, and having a atsurface engageable with said tongue.

4. In circuit controllers, a shell comprised of side and end walls, theside walls having substantially registering openings adjacent one end\wall, one of said openings comprising a semicylindrical opening havinga wedge shaped tongue, a semi-cylindrical shank journalled in saidopenings and having a surface formed of merging ilat facesarranged forrespective abutting engagement with sides of the wedge shaped tongue, agrooved guide plate mounted on the shank with the groove extendingtransversely thereof, stops on said plate at the extremities of thegroove, a cylindrical `rigid element having a rounded nose engageable insaid groove and against said stops and having an axial bore, a pinpivotally engaging an end wall in alignment with said shank and slidablydisposed in said bore, resilient means urging the element into slidingengagement with said groove, a metallic sleeve mounted on the element, apair of contacts arranged for frictional engagement by the sleeve whenthe nose of thev element abuts a stop at the end of the groove in oneextreme position when one face of the shank engages a face of the wedgeshaped tongue, the whole so arranged that the metallic sleeve is out ofengagement with said contacts when the nose of the element abuts theother stop at the other end of said groove in the other extreme positionof the shank with the other face thereof abutting the other edge of thetongue.

5. In switches, a cylindrical insulating member having a rounded nose,an axial bore and an internal shoulder, a pivoted guide pin slidable inthe bore, a spring surrounding the pin and engaging the shoulder to urgethe element downwardly on the pin, a metallic sleeve surrounding themember, a rock shaft, means for limiting the oscillations of the rockshaft, a guide plate mounted transversely ony the rock shaft and havin'ga groove in which the nose of said member is slidably guided, stop meansat the ends of said groove, a pair of resilient contacts disposed in thepath of movement of the metallic sleeve with the element uponoscillation of the rock shaft.

6. In circuit controllers, a pair of spaced resilient contacts, a bridgeelement movable toward and away from between said contacts, the bridgemember including a concentric cylindrical metallic sleeve, and means forsecuring rotation of the sleeve relative to said contacts so as to cleansaid contacts. i

7. In snap switches, a pair of parallel spaced resilient contacts, acylindrical bridge element, means operatively associated with the bridgeelement for moving it with its axis in a plane parallel to the resilientcontacts to circuit making and breaking relation with a snap action,means for axially addusting said element relative to said contacts to adifferent position for making the circuit from its position whenbreaking the circuit.

8. In snap switches, a pair of parallel spaced resilient contacts, acylindrical bridge element, means operatively associated with thebridgeelement for moving it with its axis in a plane parallel to the resilientcontacts to circuit making 110 and breaking relation with a snap action,means for axially adjusting said element relative to said contacts to adifferent position for making the circuit from its position whenbreaking the circuit, and means for rotatably-adjusting said elementduring an oscillation thereof.

ROBERT C. DA COSTA.

